A beam of white light is made up of all the colours in the spectrum. The range extends from red through to violet, with orange, yellow, green and blue in between. But there is one colour that is notable by its absence.Pink (or magenta, to use its official name) simply isn’t there. But if pink isn’t in the light spectrum, how come we can see it?

The colours present in the white light spectrum are each of a single wave length. Pink, peach, ochre, mauve, sandstone beige, harvest wheat and the rest of the Dulux swatch board all exist because they are blends of different wavelenghts which our brains interpret as single colour.